Al Gore's effort to win Ohio's 21 electoral votes has become a steep hill, according to a new Ohio Poll that shows George W. Bush's lead is up to 8 percentage points.

The poll, conducted by the University of Cincinnati's Institute for Policy Research, shows the Republican with 50 percent, Mr. Gore with 42 percent, and Green Party candidate Ralph Nader with 4 percent. The margin of error was plus or minus 3.8 percentage points.

The poll, conducted Oct. 18-25 among 666 likely voters, also shows that with less than two weeks to go before the election, there is almost no such thing as an undecided voter left in Ohio.

Only 2 percent said they don't know whom they would vote for, and the number of Ohioans who say they are definite about their choice is high among Bush supporters (87 percent) and Gore supporters (85 percent).

What this suggests is that it will be difficult for Gore to turn the numbers around in Ohio, said Ohio Poll director Eric Rademacher. Gore would have to spend a lot more time and money in the state to make an impact.

U.S. Rep. Rob Portman, R-Ohio, said the Ohio Poll is encouraging but said the Bush
Cheney campaign is not ready to chalk up Ohio in the win column.

We've always thought this will be a ground war and will have a lot to do with who gets their voters out to the polls, said Mr. Portman, who has close ties to the Bush campaign. That's why we're not going to let up.

Mr. Gore, who has consistently trailed in Ohio polling, was in the state often before the presidential debates, but has not campaigned in Ohio since Oct. 4. Mr. Bush campaigned in Toledo Thursday night, while his runing mate was in Columbus.

Since the beginning of the presidential contest, Ohio has been considered a key battleground. So far, the candidates and the political parties have spent at least $15 million in Ohio, which went for Bill Clinton in the last two elections after going Republican in the previous three presidential contests.

The Ohio Poll gives Mr. Bush a greater lead than a poll conducted Oct. 18-19 by Mason-Dixon Polling & Research for the Cleveland Plain Dealer. That poll showed a 45 percent to 41 percent lead for Mr. Bush. The margin of error was plus or minus 4 percentage points.

A statewide poll released earli er in the week by the Ohio State University's Center for Survey Research found a slim lead for Mr. Gore.

In the Ohio State poll, conducted among 1,037 registered voters from Oct. 2-Oct. 23, Mr. Gore led 45 percent to 43 percent. Poll officials, however, found a trend in favor of Mr. Bush. The margin of error was plus or minus 3 percentage points.

The Gore campaign thinks the Ohio State poll and others that show the Ohio race a near dead-heat are more accurate, said Gore campaign spokeswoman Kara Gerhardt.

All the other numbers we've seen show us going up after the third debate, Ms. Gerhardt said.

Mr. Gore will campaign again in Ohio before the Nov. 7 election, she said.

The new UC poll showed that despite millions of dollars of TV advertising and dozens of visits to Ohio by the candidates, their running mates and surrogates, Ohioans' preferences in the presidential race have changed little since April.

In the Ohio Polls since April, Mr. Bush's percentage of support has ranged from 47 percent to his present 50 percent, while Mr. Gore's support has ranged from 39 percent to 43 percent.

It really is striking how stable it has been, Mr. Rademacher said. Given what we expected going into this race, you would think Ohio would pick up a little of that volatility that you're seeing in other parts of the country. But it's been pretty steady.

Most national polls show Mr. Gore with a comfortable lead among women voters, but the Ohio Poll has Mr. Gore and Mr. Bush in a dead heat among Ohio women, with 47 percent and 46 percent, respectively.

The poll also shows that Mr. Gore is not doing well with one of the Democratic party's most faithful constituencies - organized labor. Among voters in union households, Mr. Gore has 46 percent and Mr. Bush has 45 percent.

The Cincinnati area is the best region of the state for Mr. Bush, according to the Ohio Poll. He has 59 percent support here, compared to 30 percent for Mr. Gore.

The undecided vote in Ohio, at 2 percent, is so small as to be almost a non-factor.

Sam Malone of Bond Hill, a 29-year-old Xavier student and Navy veteran, said Thursday he has yet to make up his mind because he has not heard either candidate outline specific plans on issues he is interested in, such as military affairs and higher education.